Joining two ropes with a lashing for a rappel

A recent thread about knots (bends, really) for rapelling got me thinking: what if we could eliminate bends entirely, at least from some rappelling scenarios?  Something like the picture.  

 I'm developing a different super-lightweight attachment method for spliced eyes on skinny rope, but that would be seen as a snagging hazard. Suitable for joining fixing lines, but not 2-rope rappel. The lashing between the eyes in this idea would eliminate nearly all bulk, and would even allow the eyes to pass through standard rap rings.  The likelihood of this catching in a bush's crotch or a V-shaped rock groove seems far less than any bend, and going over an edge would be trivial, so the only concern might be a twig in the eye, but such a twig would have to be small enough to fit in it that it would easily break.

This would only work with splice-able ropes, but I already have several spliced skinny rope products UIAA rated, with more in the works.  Would you rap?  The joining twine is Bio-based SK99 Dyneema, so that join is as strong as the ropes themselves

I am confused, what problem are you trying to solve here?

Your picture is less bulky, but looks more snaggable than a normal edk. All it takes is a branch or protruding feature to snag one of the three loops you have, or the rope folding around where it’s shackled together around a feature.

The Flying Dutchmanwrote:

I am confused, what problem are you trying to solve here?

The bulkiness of a knot (bend) attaching two ropes together.  Look how svelte that is.

An edk seems about the same amount of bulk with less faff and more security

Ben Zartmanwrote:

The bulkiness of a knot (bend) attaching two ropes together.  Look how svelte that is.

Sweet. So instead of dealing with a low profile knot you deal with a spliced eye on the end of the rope when you try to do anything else with it. Here’s one really good reason this is a terrible idea: while you said it fits through “normal rap rings,” a lot of rap stations have chain links that are too small to fit a bight of rope through. Get to one of those stations with this set up and you’ll be forced to leave a carabiner. Not to mention there’s now a spliced eye on the end of your rope as you’re trying to tie in, coil a rope, pull up the rope behind you, etc. 

You’re trying to solve a problem that your solution doesn’t. 

I would applaud the effort, but I can't get my hands apart. It seems to be a solution in search of a problem. 

It may be of interest that I have a patent pending for a simple device which connects two rope ends and accomplishes the desired results, but without the drawbacks mentioned above. I'm currently weaving a second prototype out of Spectra fiber. The first one was woven in China, from organic fiber. My device will accommodate rope ends with diameters from 8.2 mm to 11 mm. Production is expected to begin by the first of the year and widely available for sale by the first of April. The target price point is $19.95 USD. This illustration was submitted with my application to the US Patent Office:

I just couldn't pass up the humor in the idea of connecting two ropes without a bulky connection. My apologies to Ben. It is not a ridicule of your efforts. Innovation in climbing (and elsewhere) comes from creative thinking, trial and error. Keep coming up with fresh ideas. 

If only there was on offset bend that would work.......
I dont even want to broach the obvious issues with eye splices in climbing rope.

The title of this topic post is: Two-rope rapelling without knots at all.

A closer examination of the 'join' to unite the 2 eyes appears to be a series of knots woven together in Dyneema SK99.

The title and claim made in this thread is: "Without knots at all"

At first I thought this post was 'click-bait' (also because 'rapelling' is spelt incorrectly).

I would also caution tying knots in Dyneema - slippage is a major concern.

In the youtube video at 2:33 and 3:11 what he should have formed is a 'constrictor hitch' (not a Clove hitch).

Link: https://www.youtube.com/watch?v=b9GLp1Esins 

You will get better results with a constrictor (but abundant caution is required - need extensive field testing with all knots tied in dyneema to verify security.

Thank you all for the responses.  This focus-grouping is useful, if only to see how much some need to be brought up to speed.

The line in question is skinny: quarter-inch, or 6mm.  So the spliced eye will still thread through a link that a 9mm rope will fit through.  It's a static rope: Dyneema core with polyester cover, so it's designed to be spliced.  I'm envisioning its use as: fixing line for bigwalls, rap line for canyoneering, getting down from freesolos, etc.  Definitely not for leading, since it has no give, but useful in a dozen other ways.  Super-light, super strong, and no nylon degradation.

To the poster who thought it's as low profile as an EDK: really?  I'm at a loss to respond, since any bend in ropes makes a way bigger bundle than that.  Maybe I'll post another picture.

The lashing between them isn't really knotted: that's a standard marine lashing, where a series of half-hitches do nothing more than prevent the turns from beginning to unwind.  We uphold huge structures with lashings like this.  The amount of hitches precludes slippage--that's why there's a whole series of them.

The lashing between them isn't really knotted

That's not correct. The term "knots' includes; bends, eye knots, hitches, lashings, and decorative knots (eg macramé).

By definition, you are tying a bunch of hitches/lashings in dyneema - and hitches are a type of 'knot'.

...where a series of half-hitches do nothing more than prevent the turns from beginning to unwind.

When you put humans on the line with 'knots' (eg 'half hitches') tied in 'dyneema' (ie life critical applications) you really need to do extensive peer reviewed testing to absolutely prove that there is no risk of slippage. Extraordinary claims require extraordinary proof (when human lives are at stake).

Ben Zartmanwrote:

Thank you all for the responses.  

…

  I'm envisioning its use as: fixing line for bigwalls, rap line for canyoneering, getting down from freesolos, etc.  

Why not just use a longer rope?

Absolutely would not rap.

Ideas are great but this one should be abandoned. There are multiple issues, not least of which is that we have a perfectly good, time-tested solution to this non-problem (EDK, figure-8, whatever you prefer). As was pointed out, having one end of a rope spliced makes it non-feasible for climbing. Double ropes are used in such a way that both climbers tie into both ropes. No one is going to want to tie in with a spliced end. Plus, when an end of a rope gets worn we (climbers) cut that end off and continue using the rope. Not practical if one end is spliced.

Another issue is that your connection method is skinny rope/twine. Rope cuts rope and skinny rope cuts thicker rope reallllly quickly. Don't believe me? Tension a piece of climbing rope and then use a skinny rope in a rapid back-and-forth sawing motion. You'll slice through the rope quite quickly. Scary quickly actually. If your connection method is used and the rope gets hung up at all and has to be bounced/pulled on aggressively, I would be concerned with this happening. Especially in repeat usage.

Want to "invent" something that would be useful and welcomed? Re-make C3s.

Mark Gommerswrote:

That's not correct. The term "knots' includes; bends, eye knots, hitches, lashings, and decorative knots (eg macramé).

By definition, you are tying a bunch of hitches/lashings in dyneema - and hitches are a type of 'knot'.

When you put humans on the line with 'knots' (eg 'half hitches') tied in 'dyneema' (ie life critical applications) you really need to do extensive peer reviewed testing to absolutely prove that there is no risk of slippage. Extraordinary claims require extraordinary proof (when human lives are at stake).

It can be a "Knotted cord" if you insist. But that's just a nitpicky distraction. The system I'm playing with eliminates the tying of the two principal ropes together with a bulky bend, and also the tying of a bend in your principal Dyneema-cored rope.  Lashings of that nature are in use every day to secure all sorts of things: it is not an engineering novelty, nor is there any risk of slippage.  If eventually I put a product like that on the market, it will certainly, like my other products, undergo UIAA testing.  Will that count as peer review even if I don't ask you?

ClimbingOnwrote:

Absolutely would not rap.

Ideas are great but this one should be abandoned. There are multiple issues, not least of which is that we have a perfectly good, time-tested solution to this non-problem (EDK, figure-8, whatever you prefer). As was pointed out, having one end of a rope spliced makes it non-feasible for climbing. Double ropes are used in such a way that both climbers tie into both ropes. No one is going to want to tie in with a spliced end. Plus, when an end of a rope gets worn we (climbers) cut that end off and continue using the rope. Not practical if one end is spliced.

Another issue is that your connection method is skinny rope/twine. Rope cuts rope and skinny rope cuts thicker rope reallllly quickly. Don't believe me? Tension a piece of climbing rope and then use a skinny rope in a rapid back-and-forth sawing motion. You'll slice through the rope quite quickly. Scary quickly actually. If your connection method is used and the rope gets hung up at all and has to be bounced/pulled on aggressively, I would be concerned with this happening. Especially in repeat usage.

Want to "invent" something that would be useful and welcomed? Re-make C3s.

If you can figure out a way to make one strand of this lashing saw rapidly across the primary rope, I will absolutely abandon this idea.  But your cavil is like saying, "Table saws are dangerous.  Don't believe me? Stick your arm in one and see what happens."  Everything can be dangerous when used improperly.

For the poster who asked about longer rope, sure: I can supply custom lengths of rope up to 656 feet long.  But you don't always need that much: why not have 200-foot lengths that can be joined when needed?  Then your skinny rope can be used as a tagline, as a toprope at the crag, as a line to belay up a third--it's simply more versatile in shorter lengths.

Having a spliced loop in the end of my climbing rope would make this whole idea a non-starter for me.

Sounds like a spliced rope somehow turns into a venomous snake, nobody wants to touch it, let alone twist it into a figure eight.

So... with two rope rappels, the knot, which should NOT be able to pass through the quicklinks... is actually a safety feature. You have eliminated that.

And yeah, I don't want a spliced eye on my rope which could make it more difficult to pass through things... Also, sometimes you DO want to rap off the end of a strand.

Points for something different... but I can't see the use for recreational climbing or canyoneering. You could check with the arborists or sailers... but pretty sure they already have methods like this, ie using a skinny rope to pull a fat rope up through a tree or some rigging or something.

For all those who don't like the thought of a splice: why?  A splice retains more than 90% of the rope's strength, which a knot or bend doesn't.  I'm not suggesting it for stretchy lead lines, where I can see little value.  But for skinny tag and fixing lines, expecially Dyneema ones where a knot weakens it significantly, I can't see a downside.  I was going to say that the splice prevents accidentally rapping off the end, if you're using a belay plate specifc to the size, but a poster above seems to see rapping off the end as an advantage (!!!???).

Here's another picture for scale: you can see how low-profile the union is in relation to normal rappel rings.  You can see how thin it is in relation to two common bends in a normal lead line.  You can see, finally, how less bulky it is next to a Gormless bend and an Alpine Butterfly in the same diameter of 6mm rope.

I'm OK with everyone hating on this, by the way--new things always meet resistance from those entrenched in their methods, and it takes time to adapt to the unknown.  The broad range of rejection, with and without reasons, is instructive.  I'll go out and use this in the wild for a while, and maybe fine-tune it a little.

Yes, rapping off the ends of a rope is occasionally a desired thing to do. On rope-stretcher rappels, with the stretch in the rope you can sometimes make it to the ground just barely. In these cases one must rappel off the ends. It might sound like this is extremely rare but it isn’t. Have you climbed much?